1. Technical Field
The present disclosure relates to an alphabet input device and an alphabet recognition system in a small-sized keypad.
2. Related Art
English alphabet input devices widely used in most of small-sized keypads are provided with a toggle function. FIG. 1 is a diagram illustrating the arrangement structure of such a keypad with a toggle function. As described in FIG. 1, the keypad is composed of a plurality of buttons formed in 4×3 matrix, in which two to four alphabets are disposed in each of the buttons.
To input alphabets with the toggle function, however, a user must be aware of positions of keys and toggle order and must push buttons many times in certain cases. Furthermore, when the user wants to input alphabets in the same button by permutation, it must wait for a predetermined time to input a subsequent character or press a movement button. As a result, the efficiency of the input process is reduced.
In order to solve the problems, various methods of inputting alphabet have been proposed, for example, as disclosed in Korean Patent Application Publication No. 10-2006-29430, Korean Patent Application Publication No. 2002-55833, and Korean Utility Model Registration No. 20-0419301. FIG. 2 shows the configurations of the alphabet input devices disclosed in the above references. In the alphabet input devices, an alphabet character is input using a combination of character keys.
The alphabet input devices, however, have a problem of an ambiguity occurring in the analysis of the input permutation of certain combination of characters. For example, in case of the device of Korean Patent Application Publication No. 10-2006-29430, F is input by a combination of ‘|’ and ‘-’, and T is input by a combination of ‘-’ and ‘|’. If a user types a combination character permutation of ‘|’, ‘-’, and ‘|’ to input IT, the combination character permutation may be recognized as FI as well as TI due to the ambiguity of analysis. In case of the device of Korean Utility Model Registration No. 20-0419301, V is input by ‘V’, I is input by ‘|’, and Y is input by a combination of ‘V’ and ‘|’. If a user types ‘V’ and ‘l’ to input Y, this may be also recognized as VI. A similar ambiguity occurs in the device of Korean Patent Application Publication No. 2002-55833.
In order to solve the ambiguity, like the devices with toggle function, the devices with combination function still require an automatic time delay acting as a separator or a movement button.
On the other hand, the prior art technologies do not take into consideration usage frequency of each alphabet character in the design of the input methods and system.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.